Airfoil for inlet guide vane (igv) of multistage compressor

ABSTRACT

A vane for an Inlet Guide Vane (IGV) of a multistage compressor includes a root portion, a tip portion, and an airfoil extending therebetween. The vane is configured such that a ratio of the maximum thickness of the airfoil to a chord length (T max /C) at 50% of the span height (H) taken from the tip portion of the vane is configured to lie in the range of 0.11 to 0.12. In addition to the ratio (T max /C) at 50% of the span height (H) being in range of 0.11 to 0.12, a ratio of the maximum thickness to the chord length (T max /C) at various points along the airfoil varies with span height (H) of the vane i.e., distance taken from the tip portion of the vane and the local chord length C present at that span height H of the vane taken from the tip portion.

TECHNICAL FIELD

The present disclosure relates to an airfoil of an Inlet Guide Vane (IGV) of a multistage compressor. More particularly, the present disclosure relates to a method for manufacturing an airfoil having reduced susceptibility to vibrations experienced during operation.

BACKGROUND

Large turbomachines such as, but not limited to, a multistage compressor of a gas turbine engine, typically employ several stages of rotor assemblies mounted on a common shaft and stator assemblies mounted to a casing. The stator assemblies of such turbomachines include an Inlet Guide Vane (IGV) consisting of adjustable airfoils, or vanes, that are mounted in the casing. These vanes are generally configured to remain stationary during operation and can be actuated to alter the flow characteristics of inlet air entering the turbomachine.

U.S. Pat. No. 7,497,664 discloses a method and apparatus for fabricating a rotor blade for a gas turbine engine. The rotor blade includes an airfoil having a first sidewall and a second sidewall, connected at a leading edge and at a trailing edge. The method includes forming the airfoil portion bounded by a root portion at a zero percent radial span and a tip portion at a one hundred percent radial span such that the airfoil is configured to have a radial span dependent chord length C, a respective maximum thickness T, and a maximum thickness to chord length ratio (T_(max)/C ratio). The method further includes forming the root portion having a first T_(max)/C ratio, forming the tip portion having a second T_(max)/C ratio, and forming a mid portion extending between a first radial span and a second radial span to have a third T_(max)/C ratio, the third T_(max)/C ratio being less than the first T_(max)/C ratio and the second T_(max)/C ratio.

However, the configuration and/or geometry of these rotating blades may not be optimal for a stationary vane application; in so much as they may not assist in minimizing the possibility of vibrations during operation. As such, the vibrations caused in the airfoil may be a result of resonance between operational frequencies and natural frequencies of the vanes themselves, and these vibrations may induce undue stresses into the vanes, and may thereafter cause the vanes to experience fatigue and/or undergo failure.

Hence, there is a need for a stationary vane and a method for manufacturing the same that overcomes the aforesaid shortcomings.

SUMMARY OF THE DISCLOSURE

In one aspect of the present disclosure, a vane for an Inlet Guide Vane (IGV) of a multistage compressor includes a root portion and a tip portion that is located distally from the root portion with a span height (H) defined therebetween. The vane also includes an airfoil that extends longitudinally between the root portion and the tip portion. The vane is configured such that a ratio of the maximum thickness of the airfoil to the chord length (T_(max)/C) at 50% of the span height (H) taken from the tip portion of the vane is configured to lie in the range of 0.11 to 0.12.

Moreover, the vane includes a leading edge and a trailing edge that are separated by the chord length (C) therebetween. A ratio of the maximum thickness of the airfoil to the chord length (T_(max)/C) at various points along the airfoil additionally varies with span height (H) of the vane i.e., distance from the root portion of the vane.

In one aspect of this disclosure, a ratio of the maximum thickness of the airfoil to the chord length (T_(max)/C) at the tip portion of the vane is configured to lie in the range of 0.09 to 0.10.

In another aspect of this disclosure, a ratio of the maximum thickness of the airfoil to the chord length (T_(max)/C) is configured to lie in the range of 0.09 to 0.10 at 10% of the span height (H) taken from the tip portion of the vane; at 40% of the span height (H) taken from the tip portion of the vane; and at 60% of the span height (H) taken from the tip portion of the vane.

In another aspect of this disclosure, a ratio of the maximum thickness of the airfoil to the chord length (T_(max)/C) is configured to lie in the range of 0.08 to 0.09 at 20% of the span height (H) taken from the tip portion of the vane; and at 90% of the span height (H) taken from the tip portion of the vane.

In another aspect of this disclosure, a ratio of the maximum thickness of the airfoil to the chord length (T_(max)/C) is configured to lie in the range of 0.07 to 0.08 at 30% of the span height (H) taken from the tip portion of the vane; and at 80% of the span height (H) taken from the tip portion of the vane.

In another aspect of this disclosure, a ratio of the maximum thickness of the airfoil to the chord length (T_(max)/C) at 70% of the span height (H) taken from the tip portion of the vane is configured to lie in the range of 0.065 to 0.075.

In another aspect of this disclosure, a ratio of the maximum thickness of the airfoil to the chord length (T_(max)/C) at the root portion of the vane is configured to lie in the range of 0.10 to 0.11.

In another aspect of this disclosure, the maximum thickness (T_(max)) is selected so as to configure the vane with a natural frequency lying outside a range of operational frequencies of the vane.

In another aspect of this disclosure, embodiments disclosed herein are also directed to a method of manufacturing a vane for an Inlet Guide Vane (IGV) of a multistage compressor, wherein the method includes forming a root portion of the vane, and forming a tip portion of the vane that is distally located from the root portion with a span height (H) defined therebetween. The method further includes forming an airfoil extending longitudinally between the root portion and the tip portion such that a ratio of the maximum thickness of the airfoil to the chord length (T_(max)/C) at 50% of the span height (H) taken from the tip portion of the vane is configured to lie in the range of 0.11 to 0.12.

Moreover, the method includes forming a leading edge and a trailing edge at opposing ends of the root portion, the tip portion, and the airfoil such that the leading edge and the trailing edge are separated by the chord length (C) therebetween.

The method additionally includes forming the airfoil such that a ratio of the maximum thickness of the airfoil to the chord length (T_(max)/C) at the tip portion of the vane is in the range of 0.09 to 0.10.

The method additionally includes forming the airfoil such that a ratio of the maximum thickness of the airfoil to the chord length (T_(max)/C) is configured to lie in the range of 0.09 to 0.10 at 10% of the span height (H) taken from the tip portion of the vane; at 40% of the span height (H) taken from the tip portion of the vane; and at 60% of the span height (H) taken from the tip portion of the vane.

The method additionally includes forming the airfoil such that a ratio of the maximum thickness of the airfoil to the chord length (T_(max)/C) is configured to lie in the range of 0.08 to 0.09 at 20% of the span height (H) taken from the tip portion of the vane; and at 90% of the span height (H) taken from the tip portion of the vane.

The method additionally includes forming the airfoil such that a ratio of the maximum thickness of the airfoil to the chord length (T_(max)/C) is configured to lie in the range of 0.07 to 0.08 at 30% of the span height (H) taken from the tip portion of the vane; and at 80% of the span height (H) taken from the tip portion of the vane.

The method additionally includes forming the airfoil such that a ratio of the maximum thickness of the airfoil to the chord length (T_(max)/C) at 70% of the span height (H) taken from the tip portion of the vane is in the range of 0.065 to 0.075.

The method additionally includes forming the airfoil such that a ratio of the maximum thickness of the airfoil to the chord length (T_(max)/C) at the root portion of the vane is in the range of 0.10 to 0.11. As such, the method includes selecting the maximum thickness (T_(max)) of the airfoil such that the vane is configured with a natural frequency lying outside a range of operational frequencies of the vane.

Other features and aspects of this disclosure will be apparent from the following description and the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagrammatic illustration of an exemplary multistage compressor showing an Inlet Guide Vane (IGV) in accordance with an embodiment of the present disclosure;

FIG. 2 is a diagrammatic illustration of a vane in which embodiments of the present disclosure may be implemented;

FIG. 3 is a sectional view of the vane airfoil profile taken along section line A-A′ of FIG. 2;

FIG. 4 is a graph depicting a variation in thickness to chord ratio of the airfoil taken along various spans of the vane; and

FIG. 5 is an exemplary modal response diagram plotted for the vane in accordance with embodiments of the present disclosure;

FIG. 6 is a flowchart illustrating a method for manufacturing the vane in accordance with embodiments of the present disclosure.

DETAILED DESCRIPTION

Wherever possible, the same reference numbers will be used throughout the drawings to refer to same or like parts. Moreover, references to various elements described herein are made collectively or individually when there may be more than one element of the same type. However, such references are merely exemplary in nature. It may be noted that any reference to elements in the singular is also to be construed to relate to the plural and vice-versa without limiting the scope of the disclosure to the exact number or type of such elements unless set forth explicitly in the appended claims

FIG. 1 shows a diagrammatic illustration of a multistage compressor 100 in accordance with an embodiment of the present disclosure. The compressor 100, as illustrated in FIG. 1, may be of a type that can be employed in a gas turbine engine. The compressor 100 includes several stages of rotor assemblies 102 and stator assemblies 104 therein. The stator assemblies 104 may be associated with a shroud 106 of the compressor 100 while the rotor assemblies 102 may be independently mounted on a common rotating shaft 108. Each of the rotor and stator assemblies 102, 104 includes blades 111 and vanes 110 respectively that are configured to depend downwardly from the shroud 106 or be disposed in a coupling arrangement with the rotating shaft 108 of the compressor 100.

The blades 111 of each rotor assembly 102 are configured to rotate during an operation of the compressor 100 while the vanes 110 of each stator assembly 104 are configured to generally remain stationary to alter the fluid flow characteristics of the inlet air or gas (hereinafter simply referred to as “gas”). The compressor 100 also includes an Inlet Guide Vane (IGV) 112 that lies at the fore of the rotor and stator assemblies 102, 104. The IGV 112 is configured to impart a whirl motion to the gas as it begins to enter the compressor 100 for compression by the rotor and stator assemblies 102, 104 of the compressor 100. Moreover, the IGV 112 can be actuated to modulate the whirl motion.

The present disclosure relates to a shape of the Inlet Guide Vane (IGV) 112. FIG. 2 illustrates an exemplary vane 110 that can be employed by the IGV 112 of FIG. 1. The vane 110 includes a root portion 114 and a tip portion 116. The tip portion 116 is located distally from the root portion 114 with a span height (H) defined therebetween. The vane 110 further includes an airfoil 118 extending longitudinally between the root portion 114 and the tip portion 116. Further, the vane 110 includes a leading edge 120 and a trailing edge 122 transversely disposed at opposing ends of the root portion 114, the tip portion 116, and the airfoil 118. The leading edge 120 and the trailing edge 122, as shown, are separated by a chord length C defined therebetween.

As shown in FIG. 2, the chord length C may vary from C₂ through C₁ to C₃ between the root portion 114 and the tip portion 116. In the illustrated embodiment of FIG. 2, the chord length C gradually decreases from C₂ (at the root portion 114) through C₁ to C₃ (at the tip portion 116) i.e., C₂>C₁>C₃.

FIG. 3 illustrates a sectional view of the vane 110 taken along section line A-A′ shown in FIG. 2. FIG. 4 shows a graph depicting a variation in the maximum thickness over chord length T_(max)/C of the airfoil taken along various spans along the vane 110. Explanation to embodiments of the present disclosure will now be made in conjunction with FIGS. 2-4 collectively.

A ratio (T_(max)/C) of the maximum thickness T_(max) to the chord length C at 50% of the span height H taken from the tip portion 116 of the vane 110 is configured to lie in the range of 0.11 to 0.12. For example, if the span height H of the airfoil 118 is 100 centimetre (cm) and the chord length C of the airfoil 118 at the root portion is 10 cm, then the maximum thickness T_(max) of the airfoil 118 at 50% of the span height H taken from the tip portion 116 of the vane 110, i.e., 50 cm from the root portion 114 is about 1.175 cm (as shown in FIGS. 3 and 4), or 1.190 cm and the like.

In addition to the ratio (T_(max)/C) at 50% of the span height H being in the range of 0.11 to 0.12, a ratio (T_(max)/C i.e., T_(max)/C₃) of the maximum thickness T_(max) of the airfoil 118 to the chord length C at the tip portion 116 is configured to lie in the range of 0.09 to 0.10 (See FIG. 4). For example, if the span height H of the airfoil 118 is 100 centimetre (cm) and the chord length C of the airfoil 118 at the root portion is 10 cm, then the maximum thickness T_(max) of the airfoil 118 at the tip portion 116 may be in the range of about 0.9 cm to 1.0 cm, say 0.987 cm (as shown in FIG. 3).

Additionally, a ratio (T_(max)/C) of the maximum thickness T_(max) of the airfoil 118 to the chord length C at 10% of the span height H taken from the tip portion 116 is configured to lie in the range of 0.09 to 0.10. However, it may be noted that the maximum thickness T_(max) at 10% of the span height H taken from the tip portion 116 is lesser than the maximum thickness T_(max) at the tip portion 116 of the vane 110. Therefore, in an example, if the span height H of the airfoil 118 is 100 cm, the chord length C of the airfoil 118 is 10 cm, and the maximum thickness T_(max) of the airfoil 118 at the tip portion 116 of the vane 110 is about 0.987 cm, then the maximum thickness T_(max) of the airfoil 118 at 10% of the span height H taken from the tip portion 114, i.e., 10 cm of the span height H taken from the tip portion 116 of the vane 110 may be, 0.925 cm (as shown in FIG. 3), or say 0.94 cm and the like.

Further, a ratio (T_(max)/C) of the maximum thickness T_(max) across the airfoil 118 to the chord length C at 20% of the span height H taken from the tip portion 116 of the vane 110 is configured to lie in the range of 0.08 to 0.09. With reference to the preceding example, if the span height H of the airfoil 118 is 100 cm, the chord length C of the airfoil 118 is 10 cm, the maximum thickness T_(max) of the airfoil 118 at the tip portion 116 is about 0.987 cm, and the maximum thickness T_(max) of the airfoil 118 at 10% of the span height H taken from the tip portion 116 of the vane 110 is 0.925 cm (as shown in FIG. 3), then the maximum thickness T_(max) of the airfoil 118 at 20% of the span height H taken from the tip portion 116 of the vane 110, i.e., at 20 cm from the root portion 114, may be 0.825 cm (as shown), or 0.850 cm and the like.

Additionally, a ratio (T_(max)/C) of the maximum thickness T_(max) across the airfoil 118 to the chord length C at 30% of the span height H taken from the tip portion 116 of the vane 110 is configured to lie in the range of 0.07 to 0.08. With reference to the preceding example, if the span height H of the airfoil 118 is 100 cm, the chord length C of the airfoil 118 is 10 cm, the maximum thickness T_(max) of the airfoil 118 at the tip portion 116 is about 0.987 cm, and the maximum thickness T_(max) of the airfoil 118 at 10% of the span height H taken from the tip portion 116 of the vane 110 is 0.925 cm (as shown in FIG. 3), the maximum thickness T_(max) of the airfoil 118 at 20% of the span height H taken from the tip portion 116 of the vane 110 is 0.825 cm, then the maximum thickness T_(max) of the airfoil 118 at 30% of the span height H taken from the tip portion 116 of the vane 110, i.e., at 30 cm from the tip portion 116, may be 0.725 cm, (as shown), or 0.740 cm and the like.

As with the ratio (T_(max)/C) at 10% of the span height H taken from the tip portion 116 of the vane 110, a ratio (T_(max)/C) of the maximum thickness of the airfoil 118 at 40% and 60% of the span height H taken from the tip portion 116 of the vane 110 is also configured to lie in the range of 0.09 to 0.10. However, the individual thicknesses at 10%, 40%, and 60% may be similar or dissimilar thicknesses.

Referring to the exemplary embodiment of the vane 110 illustrated in FIGS. 3 and 4, if the span height H of the airfoil 118 is 100 cm and the chord length C of the airfoil 118 is 10 cm, the maximum thickness T_(max) of the airfoil 118 at 10% of the span height H taken from the tip portion 116 of the vane 110 is 0.925 cm (as shown from FIGS. 3 and 4), then the maximum thickness T_(max) of the airfoil 118 at 40% of the span height H taken from the tip portion 116 of the vane 110, i.e., 40 cm from the root portion 114, may be 0.935 cm while the maximum thickness T_(max) of the airfoil 118 at 60% of the span height H taken from the tip portion 116, i.e., 60 cm from the root portion 114, may be 0.950 cm (as shown), or 0.940 cm and the like.

Additionally, a ratio (T_(max)/C) of the maximum thickness T_(max) to the chord length C at 70% of span height H taken from the tip portion 116 of the vane 110 is configured to lie in the range of 0.065 to 0.075. With reference to the preceding example, if the span height H of the airfoil 118 is 100 cm, the chord length C of the airfoil 118 is 10 cm, then the maximum thickness T_(max) of the airfoil 118 at 70% of the span height H taken from the tip portion 116 of the vane 110, i.e., 70 cm from the tip portion 116 is about 0.70 cm (as deduced from FIGS. 3 and 4), or 0.675 cm and the like.

As with the ratio (T_(max)/C) at 30% of the span height H taken from the tip portion 116 of the vane 110, a ratio of the maximum thickness of the airfoil 118 at 80% of the span height H taken from the tip portion 116 of the vane 110 is also configured to lie in the range of 0.07 to 0.08. However, the individual maximum thicknesses at 30% and 80% may be similar or dissimilar thicknesses.

Referring to the exemplary embodiment of the vane 110 illustrated in FIGS. 3 and 4, if the span height H of the airfoil 118 is 100 cm, the chord length C of the airfoil 118 is 10 cm, the maximum thickness T_(max) of the airfoil 118 at 30% of the span height H taken from the tip portion 116 of the vane 110 is 0.725 cm (as shown in FIGS. 3 and 4), then the maximum thickness T_(max) of the airfoil 118 at 80% of the span height H taken from the tip portion 116 of the vane 110, i.e., 80 cm from the tip portion 116, may also be 0.725 cm (as shown), or 0.750 cm and the like.

Further, as with the ratio (T_(max)/C) at 20% of the span height H taken from the tip portion 116 of the vane 110, a ratio of the maximum thickness T_(max) of the airfoil 118 at 90% of the span height H taken from the tip portion 116 of the vane 110 is also configured to lie in the range of 0.08 to 0.09. However, the individual maximum thicknesses at 20% and 90% may be similar or may differ from one another.

Referring to the exemplary embodiment of the vane 110 illustrated in FIGS. 3 and 4, if the span height H of the airfoil 118 is 100 cm, the chord length C of the airfoil 118 is 10 cm, the maximum thickness T_(max) of the airfoil 118 at 20% of the span height H taken from the tip portion 116 of the vane 110 may be 0.825 cm (as deduced from FIGS. 3 and 4), then the maximum thickness T_(max) of the airfoil 118 at 90% of the span height H taken from the tip portion 116 of the vane 110, i.e., 90 cm from the tip portion 116, may be 0.835 cm (as shown), or 0.850 cm and the like.

Moreover, a ratio (T_(max)/C) of the maximum thickness T_(max) of the airfoil 118 to the chord length C at the root portion 114 of the vane 110 is configured to lie in the range of 0.10 to 0.11. Therefore, with reference to the preceding example, if the span height H of the airfoil 118 is 100 cm, the chord length C of the airfoil 118 is 10 cm, then the maximum thickness T_(max) of the airfoil 118 at the root portion 114 of the vane 110, i.e., at 100 cm of the airfoil 118 taken from the tip portion 116 may be in the range of about 1.0 cm to 1.1 cm, say 1.055 cm (as shown in FIG. 3), or 1.075 cm and the like.

With reference to various embodiments of the present disclosure, the maximum thickness (T_(max)) of the airfoil 118 at various points across the span H is selected such that the vane 110 may be configured with a natural frequency that is lying outside a range of operational frequencies of the vane 110. FIG. 5 illustrates an exemplary modal response diagram plotted for the vane 110 of FIG. 3 in accordance with embodiments of the present disclosure. As can be seen from FIG. 5, when the compressor 100 is driven at a rated load, for e.g., 50% load and at full engine speed, higher modes of vibration such as, for e.g., M17 and M18 have been spaced out so as to not cause resonance with the natural frequency of the vane 110. Similarly, as seen in FIG. 5, when the compressor 100 is driven at a rated load, for e.g., 100% load and at full engine speed, lower modes of vibration such as, for e.g., M8 and M9 have been spaced out so as to not cause resonance with the natural frequency of the vane 110.

Various embodiments disclosed herein are to be taken in the illustrative and explanatory sense, and should in no way be construed as limiting of the present disclosure. All directional references (e.g., aft, fore, axial, radial, above, below, upper, lower, top, bottom, vertical, horizontal, inward, outward, upward, downward, left, right, leftward, rightward, L.H.S, R.H.S, clockwise, and counter-clockwise) are only used for identification purposes to aid the reader's understanding of the present disclosure, and may not create limitations, particularly as to the position, orientation, or use of the devices and/or methods disclosed herein. Joinder references (e.g., attached, affixed, coupled, engaged, connected, and the like) are to be construed broadly. Moreover, such joinder references do not necessarily infer that two elements are directly connected to each other.

Additionally, all numerical terms, such as, but not limited to, “first”, “second”, “third”, or any other ordinary and/or numerical terms, should also be taken only as identifiers, to assist the reader's understanding of the various elements, embodiments, variations and/or modifications of the present disclosure, and may not create any limitations, particularly as to the order, or preference, of any element, embodiment, variation and/or modification relative to, or over, another element, embodiment, variation and/or modification.

It is to be understood that individual features shown or described for one embodiment may be combined with individual features shown or described for another embodiment. The above described implementation does not in any way limit the scope of the present disclosure. Therefore, it is to be understood although some features are shown or described to illustrate the use of the present disclosure in the context of functional segments, such features may be omitted from the scope of the present disclosure without departing from the spirit of the present disclosure as defined in the appended claims

INDUSTRIAL APPLICABILITY

FIG. 6 illustrates a method 600 for manufacturing the vane 110 for the IGV 112 of the multistage compressor 100. At step 602, the method 600 includes forming the root portion 114 of the vane 110. At step 604, the method 600 includes forming the tip portion 116 distally located from the root portion 114 with the span height H defined therebetween.

At step 606, the method further includes forming the airfoil 118 to extend longitudinally between the root portion 114 and the tip portion 116 such that such that the ratio (T_(max)/C) of the maximum thickness T_(max) of the airfoil 118 to the chord length C at 50% of the span height H taken from the tip portion 116 of the vane 110 is in the range of 0.11 to 0.12.

The method additionally includes forming the airfoil 118 such that the ratio (T_(max)/C) of the maximum thickness of the airfoil 118 to the chord length C at the tip portion 116 of the vane 110 is in the range of 0.09 to 0.10.

The method additionally includes forming the airfoil 118 such that the ratio (T_(max)/C) of the maximum thickness of the airfoil 118 to the chord length C is configured to lie in the range of 0.09 to 0.10 at 10% of the span height H taken from the tip portion 116 of the vane 110; at 40% of the span height H taken from the tip portion 116 of the vane 110; and at 60% of the span height H taken from the tip portion 116 of the vane 110.

The method additionally includes forming the airfoil 118 such that the ratio (T_(max)/C) of the maximum thickness of the airfoil 118 to the chord length C is configured to lie in the range of 0.08 to 0.09 at 20% of the span height H taken from the tip portion 116 of the vane 110; and at 90% of the span height H taken from the tip portion 116 of the vane 110.

The method additionally includes forming the airfoil 118 such that the ratio (T_(max)/C) of the maximum thickness T_(max) of the airfoil 118 to the chord length C is configured to lie in the range of 0.07 to 0.08 at 30% of the span height H taken from the tip portion 116 of the vane 110; and at 80% of the span height H taken from the tip portion 116 of the vane 110.

The method additionally includes forming the airfoil 118 such that a ratio (T_(max)/C) of the maximum thickness T_(max) of the airfoil 118 to the chord length C at 70% of the span height H taken from the tip portion 116 of the vane 110 is in the range of 0.065 to 0.075.

The method additionally includes forming the airfoil 118 such that a ratio (T_(max)/C) of the maximum thickness T_(max) of the airfoil 118 to the chord length C at the root portion 114 of the vane 110 is in the range of 0.10 to 0.11. As such, the method includes selecting the maximum thickness (T_(max)) of the airfoil 118 across the span height H of the vane 110 such that the vane 110 is configured with the natural frequency lying outside a range of operational frequencies of the vane 110.

In methodologies directly or indirectly set forth herein, various steps and operations are described in one possible order of operation, but those skilled in the art will recognize that steps and operations may be rearranged, replaced, or eliminated without departing from the spirit and scope of the present disclosure as set forth in the claims

Embodiments of the present disclosure have applicability for implementation in producing vanes with improved vibration resistance. With use of the embodiments disclosed herein, manufacturers may produce blades with little or no susceptibility to vibrations. Therefore, the vanes 110 of the IGV 112 disclosed herein may have a prolonged service life as they are not easily susceptible to fatigue and/or failure previously experienced in vanes manufactured using conventional methods.

While aspects of the present disclosure have been particularly shown and described with reference to the embodiments above, it will be understood by those skilled in the art that various additional embodiments may be contemplated by the modification of the disclosed machines, systems and methods without departing from the spirit and scope of what is disclosed. Such embodiments should be understood to fall within the scope of the present disclosure as determined based upon the claims and any equivalents thereof. 

What is claimed is:
 1. A vane for an Inlet Guide Vane (IGV) of a multistage compressor, the vane comprising: a root portion; a tip portion located distally from the root portion with a span height (H) defined therebetween; and an airfoil extending longitudinally between the root portion and the tip portion, wherein a ratio of the maximum thickness of the airfoil to the chord length (T_(max)/C) at 50% of the span height (H) taken from the tip portion of the vane is configured to lie in the range of 0.11 to 0.12.
 2. The vane of claim 1 further including a leading edge and a trailing edge transversely disposed at opposing ends of the root portion, the tip portion, and the airfoil, wherein the leading edge and the trailing edge are separated by the chord length (C) defined therebetween.
 3. The vane of claim 1, wherein a ratio of the maximum thickness of the airfoil to the chord length (T_(max)/C) at the tip portion is configured to lie in the range of 0.09 to 0.10.
 4. The vane of claim 2, wherein a ratio of the maximum thickness of the airfoil to the chord length (T_(max)/C) is configured to lie in the range of 0.09 to 0.10 at: 10% of the span height (H) taken from the tip portion of the vane; 40% of the span height (H) taken from the root portion; and 60% of the span height (H) taken from the tip portion of the vane.
 5. The vane of claim 2, wherein a ratio of the maximum thickness of the airfoil to the chord length (T_(max)/C) is configured to lie in the range of 0.08 to 0.09 at: 20% of the span height (H) taken from the tip portion of the vane; and 90% of the span height (H) taken from the tip portion of the vane.
 6. The vane of claim 2, wherein a ratio of the maximum thickness of the airfoil to the chord length (T_(max)/C) is configured to lie in the range of 0.07 to 0.08 at: 30% of the span height (H) taken from the tip portion of the vane; and 80% of the span height (H) taken from the tip portion of the vane.
 7. The vane of claim 2, wherein a ratio of the maximum thickness of the airfoil to the chord length (T_(max)/C) at 70% of the span height (H) taken from the tip portion of the vane is configured to lie in the range of 0.065 to 0.075.
 8. The vane of claim 2, wherein a ratio of the maximum thickness of the airfoil to the chord length (T_(max)/C) at the root portion is configured to lie in the range of 0.10 to 0.11.
 9. The vane of claim 1, wherein the maximum thickness (T_(max)) of the airfoil across the span height H is selected so as to configure the vane with a natural frequency lying outside a range of operational frequencies of the vane.
 10. A method for manufacturing a vane for an Inlet Guide Vane (IGV) of a multistage compressor, the method comprising: forming a root portion of the vane forming a tip portion distally located from the root portion with a span height (H) defined therebetween; forming an airfoil extending longitudinally between the root portion and the tip portion such that a ratio of the maximum thickness of the airfoil to a chord length (T_(max)/C) at 50% of the span height (H) taken from the tip portion of the vane is in the range of 0.11 to 0.12
 11. The method of claim 10 further including forming a leading edge and a trailing edge so as to be transversely disposed at opposing ends of the root portion, the tip portion, and the airfoil, wherein the leading edge and the trailing edge define the chord length (C) therebetween.
 12. The method of claim 11, wherein forming the airfoil includes forming the airfoil such that a ratio of the maximum thickness of the airfoil to the chord length (T_(max)/C) at the tip portion of the vane is in the range of 0.09 to 0.10.
 13. The method of claim 11, wherein forming the airfoil includes forming the airfoil such that a ratio of the maximum thickness of the airfoil to the chord length (T_(max)/C) is configured to lie in the range of 0.09 to 0.10 at: 10% of the span height (H) taken from the tip portion of the vane; 40% of the span height (H) taken from the tip portion of the vane; and 60% of the span height (H) taken from the tip portion of the vane.
 14. The method of claim 11, wherein forming the airfoil includes forming the airfoil such that a ratio of the maximum thickness of the airfoil to the chord length (T_(max)/C) is configured to lie in the range of 0.08 to 0.09 at: 20% of the span height (H) taken from the tip portion of the vane; and 90% of the span height (H) taken from the tip portion of the vane.
 15. The method of claim 11, wherein forming the airfoil includes forming the airfoil such that a ratio of the maximum thickness of the airfoil to the chord length (T_(max)/C) is configured to lie in the range of 0.07 to 0.08 at: 30% of the span height (H) taken from the tip portion of the vane; and 80% of the span height (H) taken from the tip portion of the vane.
 16. The method of claim 11, wherein forming the airfoil includes forming the airfoil such that a ratio of the maximum thickness of the airfoil to the chord length (T_(max)/C) at 70% of the span height (H) taken from the tip portion of the vane is in the range of 0.065 to 0.075.
 17. The method of claim 11, wherein forming the airfoil includes forming the airfoil such that a ratio of the maximum thickness of the airfoil to the chord length (T_(max)/C) at the root portion is in the range of 0.10 to 0.11.
 18. The method of claim 10, wherein forming the airfoil includes selecting the maximum thickness (T_(max)) of the airfoil across the span height H such that the vane is configured with a natural frequency lying outside a range of operational frequencies of the vane. 